Yes, that's right, I read that portion of the ref. doc this morn. I found the R7 (A & B) resistor the guy Larry refers to. It's a tiny surface mount part on the trace side of the board, which I'm not sure I can tackle. Never dealt with such tiny parts before. And I don't know 100% that this R7 is the Rin referred to in the ref. doc.If I remember correctly the datasheet recommends changing the value of the audio input resistor to change gain.
They don't recommend changing the feedback resistor.
Yes, that's right, I read that portion of the ref. doc this morn. I found the R7 (A & B) resistor the guy Larry refers to. It's a tiny surface mount part on the trace side of the board, which I'm not sure I can tackle. Never dealt with such tiny parts before. And I don't know 100% that this R7 is the Rin referred to in the ref. doc.
If you trace the audio in it goes through a capacitor.
Then the next resistor the trace hits is the input resistor.
Just had a look -- trace is not visible to me, which suggests I need to "trace" using multimeter... I don't trust myself to do this right.If you trace the audio in it goes through a capacitor.
Then the next resistor the trace hits is the input resistor.
Of course!You could just add a resistor on the input pin.
That would essentially be in series with the input resistor and so cut the gain.
Any R value suggestions? And do you think there'd be any SQ consequences?
I also got the Sure IRS2092 amp to drive my woofers in a future three-way Stereo setup. If the 40dB gain number is correct, for 125W into 8 ohms I get an input sensitivity of just 0.31V which seems quite low. Is this correct? I'm also looking to reduce the gain, either by adding a resistor as proposed here, or by attenuating the input level appropriately (in a PC-based DSP). I guess the former is preferred regarding the noise, right? As I'm also using amps with a 26dB gain for the mids and tweeters it would make sense to reduce the IRS2092's gain to 26 too. Otherwise I'll always have to compensate for the difference in the DSP/crossover. But given the 26dB for example, I'd get an input sensitivity of 1.58V, which is higher than my preAmp-Signal of 1Vrms. Is this still preferable to adjusting the gain in the DSP and setting the amp's gain to match the line signal level (even if not the same as the other amps)?
Today I stepped on the same rakes. ;-)
The board AA-AB32291V110 that I bought from Sure Electronics refuses to work from voltages higher than +/-70V. When the voltage drops below +/-70V it starts working. Is there some kind of protection? How to adjust it? According to their website it supposed to work on voltages up to +/-80V.
The board AA-AB32291V110 that I bought from Sure Electronics refuses to work from voltages higher than +/-70V. When the voltage drops below +/-70V it starts working. Is there some kind of protection? How to adjust it? According to their website it supposed to work on voltages up to +/-80V.
Attachments
Looks like I found it...
That's not the schematics of the Sure.
That's not the schematics of the Sure.
It is incomplete. It does not show protection details. I just removed 68V Zener Z100 and increased resistances of 2 resistors in series with TIP31 transistors (R114).
Here is the original, they just used SMD components.
http://www.infineon.com/dgdl/iraudamp7d.pdf?fileId=5546d462533600a40153569ad5ba2bf9
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